1. Field of the Invention
This invention relates to rotary sprinklers having a variable range.
2. Description of the Prior Art
The desirability of controlling the range of rotary sprinklers has long been recognized. Selective control of the direction and range of the sprinkler allows full watering of crop and lawn areas without the unwanted watering of sidewalks, roadways, and the like. In areas of heavy sprinkler irrigation, as in the Western United States, it is important that the amount of water on the land be carefully controlled for proper growth, cost efficiency, and to prevent soil erosion. It is also important that areas such as gravel roadways not be flooded because of road erosion and safety factors. The cam-cam follower invention as disclosed by L. Stanton, U.S. Pat. No. 1,593,918 has proven valuable for controlling the range of a sprinkler. For irrigational purposes, the impact or impulse type sprinkler is now heavily in use. R. D. Cooney has shown one method of using the cam-cam follower arrangement with impulse or impact type sprinklers. Other relevant patents include those of Manning, U.S. Pat. No. 2,565,926; Kennedy, U.S. Pat. No. 2,780,488; Kennedy, U.S. Pat. No. 2,999,643; Chow, U.S. Pat. No. 3,464,628; and Mullen, U.S. Pat. No. 3,405,871.
The primary disadvantages associated with the present art is that the cam is usually complicated, not readily adjustable, not easily removable, and not carried by the sprinkler head itself.